Case Report

Objective Measurement of Lisdexamfetamine’s Effects on Reading Patterns in Attention-Deficit Hyperactivity Disorder: A Case Report Utilizing Eye-Tracking Technology

Adi Diner¹, Einat Sitbon¹ and Glen R Elliot²*

¹Department of Psychiatry and Behavioral Sciences, Stanford School of Medicine, Palo Alto, CA 94304, USA

²iFocus Health, 3388 New Jersey Av, San Jose, CA 95124, USA

Submission: December 5, 2024; Published: December 17, 2024

*Corresponding author: Glen R. Elliot, iFocus Health, 3388 New Jersey Av, San Jose, CA 95124, USA JOJ Case

How to cite this article: Adi D, Einat S, Glen R E. Objective Measurement of Lisdexamfetamine’s Effects on Reading Patterns in Attention-Deficit Hyperactivity Disorder: A Case Report Utilizing Eye-Tracking Technology. JOJ Case Stud. 2024; 15(1): 555901. DOI: 10.19080/JOJCS.2024.15.555901.

Keywords: Lisdexamfetamine; Pharmacokinetic studies; Attention-deficit hyperactivity disorder; Vyvanse; Eye-tracking metrics; Stimulants

Introduction

This case report investigates the temporal dynamics of lisdexamfetamine (Vyvanse) in an adult patient with Attention-Deficit Hyperactivity Disorder (ADHD) through novel eye-tracking methodology. Using iFocus, a computer-based tool that quantifies reading patterns based on eye tracking, we tracked medication effects on reading behaviour throughout the day and compared these objective measurements with both the patient's baseline performance and subjective reports. Our findings revealed peak medication efficacy at 6 hours post-administration, with sustained elevated performance for an additional 3 hours. These results diverge from previous literature, which typically reports diminished evening effectiveness [1] and peak plasma concentrations at 4 hours post-administration according to pharmacokinetic studies [2]. This study represents the first application of objective eye-tracking metrics to measure the temporal course of ADHD medication effects, providing a potential new paradigm for monitoring treatment response. The alignment between objective measurements and patient-reported experiences suggests that eye-tracking technology may offer a valuable complement to existing methods of assessing medication efficacy in ADHD treatment.

Attention-deficit/hyperactivity disorder (ADHD) is a highly prevalent condition that can affect individuals of all ages [1]. Stimulants are commonly and effectively used to treat ADHD, and among them long-acting stimulants are becoming more common as they enable the patient to function throughout the day [2]. Pharmacokinetics indicates the concentration of d-amphetamine is highest about 4-6 hours after taking lisdexamfetamine [3] and clinical trials show effect reported as decreasing in the evening [4]. While this is valuable information for treatment guidance, a reliable biomarker will enable individualized analysis of the response to long-acting stimulants [5]. This report highlights objective measures, performed several times through the day, and indicates that lisdexamfetamine can be effective in different ways for different individuals.

An iFocus session includes reading 300-word text from a home computer, with a webcam. The texts are different middle school level non-fiction paragraphs. iFocus measure requires at least 4 baseline sessions done without medication. The baseline sessions can be done on a single or separate days. Scores were calculated per session using the iFocus algorithm, described previously [6].

Case Descriptio

A 49-year-old woman, diagnosed with combined ADHD ~20 years ago, and was treated with stimulant medication since. For the past 2 years she is treated with Vyvanse 60mg, and no additional regular medication. She finds her medication most effective in the late afternoon.

The patient’s base line sessions were done on two different days, before taking medication later in the same day. After medication was taken, sessions were performed at different time points along the day. There was a total of 19 measurements, taken over 5 days (Figure 1).

Conclusion

This case study demonstrates a sustained increase in medication efficacy throughout the day, as measured by objective eye-tracking metrics. While these findings provide novel complementary data to existing clinical trial evidence, further investigation with a larger cohort is warranted. Future studies should examine diverse patient populations and multiple ADHD medication classes to establish whether this extended duration of effect represents a common pattern among long-acting stimulant medications.

References

1. G Ayano, S Demelash, Y Gizachew, L Tsegay, R Alati (2023) The global prevalence of attention deficit hyperactivity disorder in children and adolescents: An umbrella review of meta-analyses. J Affect Disord 339: 860-866.
2. FA López, JR Leroux (2013) Long-acting stimulants for treatment of attention-deficit/hyperactivity disorder: a focus on extended-release formulations and the prodrug lisdexamfetamine dimesylate to address continuing clinical challenges. Atten Defic Hyperact Disord 5(3): 249-265.
3. J Ermer, R Homolka, P Martin, M Buckwalter, J Purkayastha, et al. (2010) Lisdexamfetamine dimesylate: linear dose-proportionality, low intersubject and intrasubject variability, and safety in an open-label single-dose pharmacokinetic study in healthy adult volunteers. J Clin Pharmacol 50(9): 1001-1010.
4. SKA Blick, GM Keating (2007) Lisdexamfetamine. Paediatr Drugs 9(2): 129-135.
5. AC Childress, M Komolova, FR Sallee (2019) An update on the pharmacokinetic considerations in the treatment of ADHD with long-acting methylphenidate and amphetamine formulations. Expert Opin Drug Metab Toxicol 15(11): 937-974.
6. GR Elliott, A Diner, E Sitbon (2024) An Objective Assessment of Effect of Stimulants on Attention in Individuals With ADHD. J Atten Disord 28(4): 451-457.